A speaker (digital speaker) equipped with a bobbin having a multilayer voice coil formed therein has been hitherto proposed (see Patent Document 1, for example). In this type speaker, a circuit board for audio signal processing is connected to each voice coil through a tinsel wire, and an audio signal is output from the circuit board through the tinsel wire to each voice coil, whereby the bobbin having the voice coils formed therein is vibrated and voices are output by vibration of a diaphragm which is based on the vibration of the bobbin.